Blades, otherwise known as oars to amateurs or non rowers, are used to propel the boat. They are long (sculling: 250–300 cm; sweep oar: 340–360 cm) poles with one flat end about 50 cm long and 25 cm wide, called the blade. Classic blades were made out of wood, but modern blades are made from more expensive and durable synthetic material, the most common being carbon fiber.
One downside of the Waterrower for me are the footrests. Whilst they are perfectly adequate if you want to row in shoes, rowing barefoot, which is something I like to do, is impossible. The plastic is completely square at the bottom and has sharp edges that cut into your heels. I also found that my shoes get caught when trying to put them in and out of the holders, which is a bit irritating.
In sweep or sweep-oar rowing, each rower has one oar, held with both hands. This is generally done in pairs, fours, and eights. In some regions of the world, each rower in a sweep boat is referred to either as port or starboard, depending on which side of the boat the rower's oar extends to. In other regions, the port side is referred to as stroke side, and the starboard side as bow side; this applies even if the stroke oarsman is rowing on bow side and/or the bow oarsman on stroke side.